1. Field of the Invention
The present invention relates to an imprint device for transferring a finely patterned structure created on a surface of a stamper to a surface of a material to be patterned, and an imprint method.
2. Description of the Related Art
Development of information technology in recent years requires further development of associated technologies in such fields as networks, software and devices. A high-level technology is required, in particular, in fabricating semiconductor integrated circuits, which have been made extremely smaller and even more integrated so as to obtain performance at higher speed with lower power consumption.
Photolithography technology for microfabricating semiconductor integrated circuits has recently shifted from KrF laser lithography with a minimum line width of 130 nm to ArF laser lithography with the width of 100 nm, thus the latter achieving a resolution higher than the former. However, even ArF laser lithography is not sufficient to be used in microfabricating a 45 nm-sized device, which is to be started as early as in 2007. Under such circumstances, promising photolithographic technologies for further higher-level microfabrication may include F2 laser lithography, extreme ultraviolet lithography, electron beam lithography, and X-ray lithography. Nevertheless, development of microfabrication brings about such problems that an initial cost of exposure equipment has been exponentially increased, and that a price of a mask to achieve a resolution equal or near to a wavelength of a light used in the microfabrication has sharply risen.
Imprint lithography has also been developed for creating a finely patterned structure. In imprint lithography, a stamper having a fine pattern complementary to a desired one is stamped onto a surface of a material to be patterned, to thereby transfer the desired fine pattern thereon. The stamper is then separated from the material to be patterned. Imprint lithography can transfer a microstructure at a 25 nm scale or less with low cost. Imprint lithography has also been applied to creation of recording bits for a large capacity recording medium, and of a pattern of a semiconductor integrated circuit.
In imprint lithography, after a stamper is used for transferring a fine pattern onto a material to be patterned such as a large capacity recording medium and a semiconductor integrated circuit, the stamper has to be separated from the material to be patterned (To simplify descriptions, even after a pattern is transferred on a material to be patterned, the material to be patterned is still referred to as the “material to be transferred” hereinafter). It is difficult, however, to separate the stamper in a vertical direction from the material to be patterned, because the stamper and the material to be patterned have been vacuum-adsorbed with each other for successfully transferring the fine pattern. To separate them, a gap needs to be created therebetween to cause a vacuum break. For example, U.S. Pat. No. 6,870,301 discloses a technique in which a stamper or a material to be patterned is tilted to induce a gap therebetween, and then, a part opposite to the gap is lifted to separate them.
In imprint lithography, however, when a microstructure in a nanometer order, for example, a microstructure created on a disk substrate for a magnetic recording medium is transferred onto a material to be patterned, there is a problem that the microstructure is too small to be successfully separated from the stamper without deformation.